Safety device



E. A. STARK SAFETY DEVICE June 28, 1938.

2 Sheets-Sheet 1 INVENTOR. 0Wflk0 A JTmez 1 Filed April 18, 1936 ATTORNEYS.

. T K I June 28, 1938. TA K 2,122,049

SAFETY DEVICE Filed April 18, 1936 2 Sheets-Sheet 2 INVENTOR Eowmeo fl. JTmQK ATTORNEY Patented June 28, 1938 UNITED STATES PATENT OFFICE Application Apr-i118,

8 Claims.

Thisxinventionrelates to safety devices for internal combustion engines of that kindemploying ;electrical ignitionand a forced feed oiling system; and, more particularly, it relates .to .a

. .type .of;safety device that operates in conjunctio'n-with the ignition system of the engine under the control, of the high pressure, forced .feed oiling system.

'Itis the principal object of this invention to i provide a safety device of the character above stated whereby the ignition circuit of the engine :will be rendered ineffective to stop the engine .shouldthe oil pressure, for any reason, fall below ,a] predetermined minimum for safe oper- .15 ,ation.

It is also an object of this invention topro- ,vide safety means of the above character, including a time delay element which will permit the usual starting of the engine regardless of its-oil condition, and provides that the safety means does not become active untilthe engine has started under its own power and there has been opportunity for anoil pressure condition to be created.

jItgistanother object of the present invention to provide' for a manual, temporary disconnection of the safety ,device to permit operation of the engine regardless of its oil-condition-when such operation is desired.

l Morespecifically stated, the presentinvention resides in the provision of a safety device for use in, connection with various conventional typesof automobile engines, to be operated undercontrol of theoilpressure in the engine's ,35 oiling system, and. including, .as a part thereof, a, shunt circuit that will automatically be closed in the event of lack or failure of oil pressure, thereby toshunt the ignition circuitfrom the spark plugs of the engine to thereby render'the engine 40 inoperative.

Other objects of the invention reside in "the details of construction of the various parts, in their combination and in their-mode of oper- :ation,, as will hereinafterbe fully described.

In accomplishing these, and other objects of .,the invention, ;I have provided the improved detailsgpf construction, the preferred forms of which, are illustrated in the accompanying drawin s, wh

Iii-Fig.4, is a view that diagrammatically illusjtrates the safety device as used in combination withggthe ignition andstarting system of the .usual type of automobile engine.

Fig. 2 is a side view of the auxiliary switch 155 vdevicecem.p ayed in the safety system.

v SAFETY DEVICE Edward A. Stark, Waldport, Oreg.

1936, Serial No. 75,151-

Fig. 3 is a sectional view of the auxiliary switch as seen on the line 3-3 in Fig. 2.

Fig. 4 is a front elevation of the control unit of the safety system as connected with the oil pressure line; a part of the housing of the unit and'a part of the cylinder of the time delay element being broken away for better illustration.

Fig. 5 is a side view, and partial section of the control unit as seen in Fig. 4.

Referring more in detail to the drawings .-In order to better explain the character and .mode of operation of the present safety system. I have, in Fig. l, diagrammatically illustrated it as operatively connected with the oiling ignition and starting systems of a conventional type of automobile engine. In this view, I designates the-usual current generator which in use is operatively connected with the engine so that, in the normal operation of the engine, it generates the necessary electrical energy for energizing the ignitionsystem and also for supplying electrical ner y to charge the storage battery which is designated by reference character 2. The negativepole of the generator I is grounded through the frame structure of the motor or vehicle by means of a circuitconnection 3'. The positive poleof the generator is connected by means of a circuit wire 3, or the like, with an ammeter designatedat 4, and awire 5 connects the am- .meter with the positive side of a starting switch designated at'6. The positive side of the battery 2 is connected to the starting switch by wire I .and the negative side of the battery is grounded to the vehicle frame by means of a connection Ill. The starting motor for the engine is designated at 9 and this is connected at its positive side with the negative side of the starting switch 6 by, a circuit connection 8, and at its negative side it is grounded through the mediacy of a connection indicated at H. The above arrangement, provides that upon closing the starting switch 6, a circuit is closed through the starting motor which draws upon the reserve of electrical energy stored in the battery 2 and the starting motor, being operatively connected with the engine, sets the latter in motion. Operation of ;the engine at a predetermined speed, in turn, drives the generator I, which creates electrical energy-for energizing the ignition system, as is well understood in this art.

The ignition system also includes a starting switch l2 which is connected by a wire I3 with the ammeter-A and by wire l5 with a circuit breaker point Hi. There is also the usual circuit breaker arm l6, which, in its normal operation of oscil- .55

a contact 2!, which, in turn, is connected with.

the primary winding 22a of an inductance coil, .22 having its negative pole grounded as indicated at 23. The secondary winding 22b of the inductance coil is grounded at one side, as at 24, and

has its other side connected by wire 25 with the central pole 26 of a distributor 21, which, through I connection 28, supplies electrical energy to the various spark plugs, indicated at 29, of the motor in proper timing. The connections between the distributor and spark plugs are indicated at 23, and the spark plugs are grounded in'the usual manner, as indicated at 33.

It is apparent that, should the ignition circuit be grounded before reaching the induction coil 22,

this would interrupt the energization of the spark plugs and, as a result, the engine would cease to operate. Therefore, it will here be explained that the present safety device contemplates a means whereby such grounding of the circuit to the induction coil will be effected incident to lack of a predetermined oil pressure occurring during the normal operation of the engine.

By reference to Fig. 1, which diagrammatically illustrates the arrangement of parts, 3| designates a conduit or pipe connection with the oil pressure line which is connected at any suitable point with the oiling system, and also which may be a connection that leads to an oil pressure indicator, as designated at 3m. Normally such an indicator is disposed upon the instrument board of the automobile in which the engine is installed. A branch pipe 3lb leads from the line 3! and connects with one end of a Bourdon tube 32. When the engine is in operation, and the supply of oil is satisfactory, or in excess of a necessary for safe operation, the pressure of oil will cause a slight movement of the tube toward straightening out, thereby to lift its free end away from a contact point designated at 33, to break a shunting circuit, presently to be described.

In its intended operation, the Bourdon tube serves as an automatic switch for automatically closing a shunt circuit which renders the induction coil ineffective and thereby interrupts'the flow of electrical energy to the spark plugs. i With the motor standing idle and no pressure in the oiling system, the Bourdon tube will be engaged with the contact 33.

The shunt circuit which the safety device employs in the present instance comprises a circuit wire 34 which leads from the arm I6 to one side of an auxiliary switch 35 and a wire 34 which leads from the other side of the switch 35 to a contact member 36 employed in the control unit, being a principal part of the device, and which is disto one'pole of the electro-magnet.

dotted line position in Fig. 3.

indicated at 39. Thus, it is apparent that, with the switch arm 3? closed against contact 36, and with the auxiliary switch closed and with no oil pressure in the Bourdon tube, the ignition circuit, normally connected to the induction coil 22, will be grounded through the arm l6, and connections 34, 35, 34, 36, 31, 38, 33, 32, 3Ib and 39. So long as either the switch 35 or 31 is open, or the Bourdon tube contacting the point 33, the shunt circuit will be open.

The safety unitemployed in the present system has for its purpose to control this shunt circuit, and it will now be described: Referring particularly to Figs. 4 and 5, this illustrates the control unit which, as a matter of convenience, might be 7 mounted upon the dash board 40 of the vehicle.

A bracket member 4| serves as the. mounting member for -the unit and this bracket is indicated as beingattached to the dash board by the bolts 42 at its upper and lower ends. Mounted on the upper end portion of the bracket, and insulated therefrom by means of the spacer 43, is an electro-magnet, designated in its entirely by reference numeral 44. A circuit connection 45 leads from the'negative side of the starting switch 6 The other pole of the magnet is grounded by a connection indicated at Ma. The armature 46 of the electromagnet is fixedly connected to the yieldable switch arm- 31 and also has connection with a time delay element designated at 41.

The time delay element, as best illustrated in Fig. 4, comprises a cylinder 48 containing a piston 49 which is connected by rod 490/. with the outer end of armature 43. The cylinder contains a hydraulic medium and the piston is of a valve type of construction which permits it to be readily lifted and slowly returned under action of spring arm 31, to normal position byleaking of the hydraulic medium from the lower to the upper side of the piston.

With the connections as so far described, it is apparent that when a circuit is closed through the electro-magnet 44, the armature 46 will be lifted, thereby to break the electrical connection between the arm 31 and the contact 36, and this connection will remain broken until the time delay elem'ent'has permitted the return of the arm 3'! to its normal position, as indicated in Fig. 4. It will be explained here that in the present instance, a time delay interval of 30 seconds has proven to be quite satisfactory.

For a purpose presently apparent, I have included the auxiliary switch 35 in the grounding connection between the point 36 and the arm I6.

This switch is actuated by means of a manually moved lever 50 connected to a shaft 5| rotatably mounted in friction bearings 52 and 53, which are formed as a part of a supporting bracket 54. This bracket may be attached to the dash board adjacent the control element. Also, fixed on the shaft 5|, is a pivotally suspended weight 59 adapted normally to form a circuit connection between contacts 60 and 6! with which the wires 34 and 34', respectively, connect.

By rotation of the shaft 5| through the mediacy of lever 50, the weight 59 will be lifted to the It is intended, however,'that the Weight will swing down of its own accord upon the movement of the automobile over an uneven road surface, thus limiting the time or movement of the automobile while the motor is operating without proper oil in its lubricating system.

Assuming that the device is constructed in the manner described, and that it is operativelyconnected invthe system, as illustrated,=its operation wouldbe'as followsz I With the auxiliary switch closed, and theswitch arm 31 engaged with-the contact 36 and the en'- gine at rest, the Bourdon tube will normally engage with the contact 33. Upon closing the starting switch 6, current will flow through the starting motor 9 to start the engine. Coincident with the closing of the starting switch, the circuit will be closed through the electro-magnet 44, which will lift the armature 46 upwardly, thereby disconnecting the circuit between the switch arm 31 and point 36. Assuming that there is a satisfactory oil condition in the engine, the Bourdon tube will be expanded and thereby disengaged from the circuit contact 33. As soon as the starting switch 6 is opened, the circuit to the electro-m'agnet is opened and the time delay element 4'! starts functioning. Thus, after a predetermined time interval, the arm 31 again engages the contact, 36. Assuming that the oil condition is unsatisfactory in the engine, the Bordon tube will then complete the grounding connection and the supply of electrical energy to the spark plugs will be shunted through this connection to the ground 39. In the event that the oil pressure is satisfactory, the grounding circuit will remain open, and this will be the case so long as there is enough oil or enough pressure in the system to expand the Bourdon tube end disconnected from the point 33. In the event that the oil supply should fail while the vehicle was at some distance from a source of oil supply, the operator, naturally, would desire to continue on to the source of oil supply. Therefore,

.to open this grounding circuit and permit a continued operation of the engine in a normal manner, the auxiliary switch 35 would be opened.

It will be here mentioned that the auxiliary switch is only held in open position frictionally and that the normal vibration of the vehicle will eventually cause the weight 59 to drop into circuit closing contact with the parts 60 and SI; the object of this being to prevent injury to the engine should the operator inadvertently overlook the closing of this switch.

It is apparent with the present safety device it would be impossible for the vehicle to operate under an unsatisfactory oil condition as provided for through the mediacy of the time delay element 41 and the auxiliary switch.

The minimum pressure at which the device may be set to function may be controlled by the setting of the contact 33, which, as illustrated in Fig. 4, comprises a set screw that is inwardly and outwardly adjustable relative to the movable end of the Bourdon tube.

Having thus described my invention, what I claim as new therein, and desire to secure by Letters Patent, is-- 1. The combination with an engine of the character described, having an ignition circuit and having an oiling system maintained under that will be opened incident to starting of the engine and closed after a predetermined interval.

2. The combination with an engine of the character described, having an ignition circuit and having an oiling system in which the oil is placed under'pressure by operation of the engine; of a safety device including a circuit for grounding the ignition circuit to render the engine inoperative and a switch'in the grounding circuit operable under control of pressure of oil in the oiling system, to close the grounding circuit when the pressure falls below a predetermined amount; said grounding circuit including also a time delay switch adapted to be opened incident to starting the engine and to close after a. predetermined time interval.

3. The combination with an engine of the character described, having a starting circuit, an ignition circuit and a pressure oiling system operated by the engine; of a safety device including a circuit for grounding the ignition circuit to render the engine inoperative and a control switch and time delay switch in the grounding circuit; said control switch being operatively connected with the oiling system and operable to open or close the grounding circuit under the influence of oil pressure in the system and said time delay switch being opened incident to closing of the starting circuit.

4. The combination with an engine of the character described, having an ignition circuit and a pressure oiling system, of a safety device including a circuit for diverting the ignition circuit to render the engine inoperative, a switch in the latter circuit, operable under control of pressure of oil in the oiling system, to close the circuit when the oil pressure falls below a predetermined minimum, a normally closed time delay switch in the diverting circuit, and an electro-magnet with means whereby it is caused to be energized incident to starting the engine, for opening the time delay switch. a

5. The combination with an engine of the character described, having a starting circuit under control of a starting switch, a pressure oiling system and an ignition circuit, of a safety device including a circuit for grounding the ignition circuit to render the engine inoperative, an automatic switch in the circuit operable by pressure in the oiling system, to close the circuit when the oil pressure is below a predetermined minimum, a time delay switch in the circuit, an electro-magnet having an energizing circuit adapted to be closed incident to closing the starting switch to open the time delay switch and maintain the grounding circuit open for a predetermined time interval.

6. A system as in claim including a normally closed auxiliary switch in the grounding circuit and means for manually opening the auxiliary switch.

'7. A system as in claim 5 including a normally closed auxiliary switch in the grounding circuit, and means whereby said switch may be manually opened; said auxiliary switch including a weighted switch arm arranged to close by gravity, manual means for moving it to open position having friction bearings for yieldingly retaining the arm in open position.

8. The combination with an internal combustion engine having a starting circuit including a normally open switch, an ignition circuit, and a pressure oiling system, of a safety device comprising a circuit for grounding the ignition circuit, a switch in said circuit movable under control of the pressure of oil in said oiling system touclosed position when the pressure is below a predetermined amount, a normally closed time delay switch in said grounding circuit, an electrically energized. means for actuating the time delay switch to open position; said latter means having a circuit therefor connected with the starting circuit in a manner to be energized only during energization of the starting circuit, to open the last named switch for a predetermined interval following the starting of the engine, and an auxiliary switch in the ignition grounding circuit adapted to be manually opened.

EDWARD A. STARK. 

